For a holiday gift in 2011, my digital consultancy, AnswerLab, bought every employee a Fitbit personal activity tracker. The idea was to promote our culture of wellness and activity.

Fitbit, a small gadget that clips on your clothes, has a small accelerometer and altimeter to track the steps you take and stairs you climb, and syncs that data with free online tools and dashboards. Countless research studies have shown that physical activity drives better health and longevity. So, we are constantly looking for ways to entice our employees to be more active.

In May, we issued a personal challenge to all employees. Anyone who achieved a 10,000-step average daily balance (the recommended amount of activity, according to Fitbit) was entered into a drawing for a second $400 technology gift from the company.

Naturally, our employees have high expectations for the user experience of the digital products we use. It turns out, over the last five months, Fitbit has delivered a best-in-class customer experience in every way. (It's not a client of AnswerLab, by the way.)

Here's what you can learn about user experience best practices from Fitbit:

1. Don't satisfy customers. Delight them!

We've done some dumb things with our Fitbits. We've dropped them behind the toilet, washed them, sent them to the dry cleaners, lost them while traveling, you name it.

The first time a team member called Fitbit customer support about a lost Fitbit, the company sent us another oneat no cost, no questions asked. When Fitbit moved into the building next door to us in San Francisco, a customer support rep personally delivered a replacement Fitbit to another team member. What happened to the laundered Fitbit? To our amazement, it still worked. In all of these instances, our team wasn't merely satisfied, we were amazed.

Think about how you can over-deliver to customers in a cost-effective way, and they'll be customers for life.

2. Tailor your product to basic human needs and behaviors.

Prior to purchasing the Fitbit, AnswerLab researchers investigated several personal activity trackers. They also tested them for a few weeks to see which one would best meet our needs. Fitbit won because it embraced basic human behaviors. Here's how.

Fitbit has an online "leaderboard," on which each employee can see how everyone else at the company ranks in total number of steps over a seven-day and 30-day period. Motivated by competition, the team members have dramatically increased daily activity levels. From pacing while talking on conference calls, to walk-n-talks along the Embarcadero, to standing rather than sitting at the computer, our team now moves.

Everyone likes praise, and Fitbit also gets that. The tool issues badges, challenges, and positive feedback for achieving various milestones like lifetime miles of 250 or 500, and Helicopter and Skydiver badges for climbing flights of stairs. It issues weekly progress reports to help track against fitness goals.

To help users feel a reward, Fitbit tracks progress from multiple dimensions: weight, fitness goals, food plans, and sleep. For example, it lets you know the percentage by which you've increased activity levels.

3. Don't add features for features' sake.

Fitbit capitalizes on social interaction and "gamification" to motivate our fitness goals. The leaderboards and public/private groups have been developed with a keen understanding of what actually gets humans moving.

A different personal activity tracker we evaluated included a game that enabled users to build a virtual world. This adds no value because it lacks the real-world social interaction to drive motivation.

4. Make the important tasks effortless.

Fitbit's progress-tracking tools and community features are online, in a feature-rich website. To access them you sync your Fitbit, which the company has made a completely seamless and effortless task. A long battery life means you rarely need to dock the Fitbit and that your online stats will update anywhere in the office, as long as someone has a base station connected to their USB drive.

5. Encourage bonding and attachment.

Fitbit is so in tune with human psychology that many of us have grown a deep affection for the small clip-on gadget. One of our senior researchers caught a cab in Florida, realized her Fitbit had fallen off, made the driver return to the research facility where she originated, searched the elevator, sprinted back to the eye tracking room, found the Fitbit on the floor, and dashed back to the cab.

We long for the Fitbit greeting, "Howdy, Amy; walk me," like coming home to a much-loved pet. In fact, many of us wonder if we exercise without the Fitbit on if we've really exercised at all. Our attachment to our Fitbits makes us huge promoters of the product to friends, family, and colleagues.